language: ruby
cache: bundler
rvm:
  - 2.5
  - 2.4
  - 2.3
gemfile:
  - gemfiles/rails_52.gemfile
  - gemfiles/rails_51.gemfile
  - gemfiles/rails_50.gemfile
  - gemfiles/rails_42.gemfile
notifications:
  email: false

# for 2.5.0 until 2.5.1 is released: https://github.com/travis-ci/travis-ci/issues/8978
before_install:
  - gem update --system